let a:string="zs"
let age:number=18//自动推断
console.log(a.toUpperCase())
let changeNameToUpper=(name:string)=>{
    let a=name.toUpperCase()
    return a
}
console.log(changeNameToUpper("sss"))
console.log(changeNameToUpper("yyy"));
let bb:(a:number,b:number)=>number=(a:number,b:number)=>{
    return a*b
}
let cc:(a:string,b:string)=>string=(a:string,b:string)=>{
    return a+b
}
let dd=(a:string,b:number)=>{
    return a+b
}
console.log(bb(2,3))
console.log(cc("ss","yy"))
console.log(dd("yy",6))